Automatic hydraulic saddle lock



XR 390453635 Si? y l D. R. SMITH Erm. AUTOMATIC HYDRAULIC 'SADDLE Loox July 24, 1962 lFiled April 5, 1961 f im;

S'Sheets-Sheet 1 3 Sheets-Sheet 2 July 24,1962 nf. R; SMITH Erm,

' AUToMATic HYDRAULIC SADDLE Lox" Filed- April 5, 1961 .Illl. 3@

' July-.12.42 1962 D. R. SMITH ETAL AUTOMATIC HYDRAULIC SADDLE Locx 3 Sheets-Sheet 3 Filed April 5, .1961

L M ,j fm 1mg. will 1%/ M Z MQW/@ x 2, ,z I vw Q .DBBDDDDIDLT n WQ, M Q D @U m1 Q m/ .W\ v/ V m m The'prcsent invention relates to apparatus for stowing a towed body aboard a vessel.

In variable depth sonar apparatus a body is'towed astern the vessel in which the sonar transducer and associated equipment is used. When the sonar equipment is not in use the towed body must be stowed aboard the vessel. According to present knowledge this may be accom'- plished by maintaining tension of the towing cable to hold the body in a saddle or by clamping the body with movable forks. Locking by maintaining cable tension has limitations in that as the body becomes larger and heavier the cable tension required becomes very large. Locking with forks is also not suitable for large, heavy bodies.

The present inventor has found a way of clamping lwglli hx o th'b'ody having a`t`owirig" cablexd `thereto., a thriitblo'cinunted o'n`the`/e`s'slahd`ad`ap'ted to receive the tow arm and a locking pin adapted to pass through the opening in thetow arm and in the throat block and lock the tow arm in the throat block. A feature of the present invention is that the locking pin is actuated by a spring and a hydraulic piston and must be retracted against the force of this spring. If for any reason the associated equipment for retracting and extending the locking pin should fail the pin will remain in the locked position, held there by the spring. Further,

,in accordance with a feature of the invention a switch is provided whichis operated by the locking pin in its extended position to extinguish the warning light,which indicates that the locking pin is completely seated. A further feature of the invention is the provision of a switch mounted in the throat block and adapted to be operated by the tow arm so that the switch is actuated when the tow arm is fully seated in throat block, operation of the switch causing the release of the locking pin which is moved into the locking or extended position by the spring and the hydraulic piston.

In drawings which illustrate an embodiment of the invention:

FIGURE 1 is a plan view of the towing apparatus xed to the stern of a vessel for towing for variable depth sonar,

FIGURE 2 is a vertical section through the throat block and tow arm showing the tow arm in the fully engaged position,

FIGURE 3 is a schematic diagram of the electrical` and hydraulic circuits for operating the locking pin, and,

FIGURE 4 is a vertical section through the locking pin showing the throat block, the tow arm and warning light switch.

FIGURE l shows the towing apparatus which is mounted at the stern of a vessel for towing a variable depth sonar body. This apparatus comprises a toller mounted on the frame 11 over which the cable C (shown in dotted lines) passes to a winch, not shown. 'The cable passes over a roller 12 mounted above the throat block 13.' Saddle side rollers 14 and 15 are mounted on either side of the throat block and adapted United StatessPatent C) ICC i to deflect the cable into the throat block 13. To facili-h tate this the throat' block 13 is provided with faces 16 fully engaged in the throat block 13, the interior por-v tion 19 of the throat block 13 being shaped to conform with the shape of the tow arm 18, The pin hole 20 .lgsgirovided through the tow arm 18 and in registry with corresponding holes in the throat block 13. A cam switch 21 is positioned adjacent the opening 19 in the throat block 13 and is adapted to be operated when the tow arm' 18 is fully seated in the throat block 13 and causes an electrical circuit to be opened. The cam 21 is spring loaded by a spring 22. The plurality of openings 23 are provided in the throat block 13 in which heating elements may be positioned to heat the throat block and prevent the tow arm from freezinginto the throat block, or the locking pin being frozen in its locked position.

FIGURE 3 shows the schematic diagram of the electrical and hydraulic circuitry associated with the operation of the locking pin. The locking pin 24 is shown schematically as passing through the throat block 13 and the tow arm 18. The cam switch 21 actuates a ,solenoid 25 to which is connected a hydraulic valve 26.

This valve controls the flow of hydraulic fluid from an accumulator 27 and pump 28 to a hydraulic cylinder 29 which may retract the locking pin 24. In the position as shown-in FIGURE 3 the valve 26 is positioned to cause the piston 30 in the hydrauliccylinder 29 to move to the left and force the iocking pin int'o the extended position. The operation of the locking pin is also effected by means of the spring 31. When the switch 21 is open the solenoid 25 causes the hydraulic valve 26 to move to a position in which the locking pin is engaged with the throat block and the tow arm. The switch 21 is opened by the tow arm seating in the throat block 13. A switch 32l is provided for retracting the locking pin and when this switch is closed the solenoid is operated causing the valve 26 to move to a position which results in the piston 30 of the hydraulic cylinder 29 being moved to the right and the locking pin being retracted. In order to actuate the solenoid 25 a battery 33 is included inthe circuit.

A warning light switch 34 is included in the throat block 13 and this switch 34 is normally closed causing the warning light 35 to -be lit. When the locking pin 24 is fully engaged through the throat block 13 and tow arm 18 the warning light switch 34 is opened and the light 35 extinguished indicating that the locking pin is fully extended.

If for any reason the locking pin should move after it has been extended, then the warning light switch 34 will reclose and indicate that the locking pin is not fully engaged.

FIGURE 4 shows a vertical section through the locking pin 24, the throat block 13 and a tow arm 18. The warning light switch 34 is shown mounted on the opposite sides of the throat block from the locking pin 24, As illustrated, when the tow arm 18 is fully seated in the throat block 13 and the hydraulic cylinder 29 conditioned to extend the locking pm, the spring 31 will drive the locking pin 24 through the aperture in the throat block 13, through the pin 'noie .i0 in the tow arm 18 and through the aperture on thc fax' side of the tnt-cat block 13 into engagement with the warning light switch 34. The switch will be opened and the warning light extinguished indicating that the locking pin is in its extending position.

The system is fail safe since the pin 24 is in the locked Patented July 24, 1962l 3 position when the electric power is off. There is also an accumulator 27 n the hydraulic circuit to provide emergency hydraulic power and to hold the pin 24 in the locked position. The pin 24 may be retracted by holding closed a switch which overrides the one at the throat block. 5.r

This lmoves the solenoid to retract position. The locking pin will be retracted against the spring by the hydraulic cylinder and the tow arm will rnove down out of the throat block when the tow cable is payed out.

This releases thel spring loaded vcam which closes the 10 normally closed switch in the throat block. The retract switch button can now be released as the electric circuit will remain closed through the cam switch, holding the pin in the unlocked position. In case of a failure in the automatic circuit, a switch can be closed making the 15 circuit non-automatic but still remote controlled. Pushing the retract button and releasing it will cause the pin to lirst move out and then into the lock position.

We claim:

1-. In a 'blejeattritonarnapparatuwherein 20 "Vesseij'mans for locking the body in a stowed position `aboard the vessel comprising a tow arm'xed to said said tow arm, a locking pin adapted to pass through an opening in said tow arm and in said throat block and to lock said tow arm in said throat block, and a switch positioned in said throat block and adapted to operate when said tow arm is fully seated in said throat block, said switch being connected to means for operat- 3. Apparatus according to claim 2 wherein said retracting means comprises a hydraulic cylinder actuated by a source of hydraulic pressure, said switch being operable to disconnect said hydraulic cylinder from said source of hydraulic pressure, to cause said pin to move to the locked position.

4. Apparatus according to claim l whereby said throat g block is provided with a plurality of heating elements positioned longitudinally thereof.

References Cited in the le of this patent UNITED STATES PATENTS 2,599,200 Rogers June 3, 1952 

